package demo1;

import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class Demo {
    public static void main(String[] args) throws Exception {
        //需求：调用User对象的sayHello方法

        //1.传统模式：new对象，调方法
        User u1 = new User();
        u1.sayHello();

        //2.使用反射机制
        Class cls = Class.forName("demo1.User");
        User u2 = (User) cls.newInstance();
        u2.sayHello();

        //3.使用Spring容器来管理对象
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext("demo1");
        User u3 = context.getBean(User.class);
        u3.sayHello();

    }
}
